CF1255A Changing Volume

Bob watches TV every day. He always sets the volume of his TV to $ b $ . However, today he is angry to find out someone has changed the volume to $ a $ . Of course, Bob has a remote control that can change the volume. There are six buttons ( $ -5, -2, -1, +1, +2, +5 $ ) on the control, which in one press can either increase or decrease the current volume by $ 1 $ , $ 2 $ , or $ 5 $ . The volume can be arbitrarily large, but can never be negative. In other words, Bob cannot press the button if it causes the volume to be lower than $ 0 $ . As Bob is so angry, he wants to change the volume to $ b $ using as few button presses as possible. However, he forgets how to do such simple calculations, so he asks you for help. Write a program that given $ a $ and $ b $ , finds the minimum number of presses to change the TV volume from $ a $ to $ b $ .

Each test contains multiple test cases. The first line contains the number of test cases $ T $ ( $ 1 \le T \le 1\,000 $ ). Then the descriptions of the test cases follow. Each test case consists of one line containing two integers $ a $ and $ b $ ( $ 0 \le a, b \le 10^{9} $ ) — the current volume and Bob's desired volume, respectively.

For each test case, output a single integer — the minimum number of presses to change the TV volume from $ a $ to $ b $ . If Bob does not need to change the volume (i.e. $ a=b $ ), then print $ 0 $ .

In the first example, Bob can press the $ -2 $ button twice to reach $ 0 $ . Note that Bob can not press $ -5 $ when the volume is $ 4 $ since it will make the volume negative. In the second example, one of the optimal ways for Bob is to press the $ +5 $ twice, then press $ -1 $ once. In the last example, Bob can press the $ +5 $ once, then press $ +1 $ .